User equipment, radio network node and methods performed therein for handling communication in a wireless communication network

ABSTRACT

Embodiments herein disclose, e.g., a method performed by a user equipment, UE, for handling communication in a wireless communication network, wherein the UE is in a connected mode in a first beam connected to a radio network node. The UE detects a beam failure of the first beam and transmits, to the radio network node, a preamble of a random access procedure in a second beam, wherein the preamble or a random access resource used for the preamble is associated with a beam failure recovery. The UE then receives a random access response, RAR, from the radio network node, wherein the RAR includes an uplink, UL, grant but without a temporary identity that is used by a medium access control, MAC, entity during a random access procedure.

TECHNICAL FIELD

Embodiments herein relate to a user equipment (UE), a radio network nodeand methods performed therein regarding wireless communication. Inparticular, embodiments herein relate to handling communication, e.g.transmitting random access responses (RAR), in a wireless communicationnetwork.

BACKGROUND

In a typical wireless communication network, user equipments (UE), alsoknown as wireless communication devices, mobile stations, stations (STA)and/or wireless devices, communicate via a Radio Access Network (RAN) toone or more core networks (CN). The RAN covers a geographical area whichis divided into service areas, also referred to as cells, with eachservice area being served by a radio network node e.g., a Wi-Fi accesspoint or a radio base station (RBS), which in some networks may also becalled, for example, a gNodeB, a NodeB, or an eNodeB. The service areais a geographical area where radio coverage is provided by the radionetwork node. The radio network node operates on radio frequencies tocommunicate over an air interface with the UEs within range of the radionetwork node. The radio network node communicates over a downlink (DL)to the UE and the UE communicates over an uplink (UL) to the radionetwork node.

A Universal Mobile Telecommunications network (UMTS) is a thirdgeneration (3G) telecommunications network, which evolved from thesecond generation (2G) Global System for Mobile Communications (GSM).The UMTS terrestrial radio access network (UTRAN) is essentially a RANusing wideband code division multiple access (WCDMA) and/or High SpeedPacket Access (HSPA) for user equipments. In a forum known as the ThirdGeneration Partnership Project (3GPP), telecommunications supplierspropose and agree upon standards for e.g. third generation networks, andinvestigate enhanced data rate and radio capacity and upcominggeneration networks. In some RANs, e.g. as in UMTS, several radionetwork nodes may be connected, e.g., by landlines or microwave, to acontroller node, such as a radio network controller (RNC) or a basestation controller (BSC), which supervises and coordinates variousactivities of the plural radio network nodes connected thereto. Thistype of connection is sometimes referred to as a backhaul connection.The RNCs and BSCs are typically connected to one or more core networks.

Specifications for the Evolved Packet System (EPS), also called a FourthGeneration (4G) network, have been completed within the 3GPP and thiswork continues in the coming 3GPP releases, for example to specify aFifth Generation (5G) network. The EPS comprises the Evolved UniversalTerrestrial Radio Access Network (E-UTRAN), also known as the Long TermEvolution (LTE) radio access network, and the Evolved Packet Core (EPC),also known as System Architecture Evolution (SAE) core network.E-UTRAN/LTE is a variant of a 3GPP radio access network wherein theradio network nodes are directly connected to the EPC core networkrather than to RNCs. In general, in E-UTRAN/LTE the functions of an RNCare distributed between the radio network nodes, e.g. eNodeBs in LTE,and the core network. As such, the RAN of an EPS has an essentially“flat” architecture comprising radio network nodes connected directly toone or more core networks, i.e. they are not connected to RNCs. Tocompensate for that, the E-UTRAN specification defines a directinterface between the radio network nodes, this interface being denotedthe X2 interface.

With the emerging 5G technologies such as New Radio (NR), the use ofvery many transmit- and receive-antenna elements is of great interest asit makes it possible to utilize beamforming, such as transmit-side andreceive-side beamforming. Transmit-side beamforming means that thetransmitter can amplify the transmitted signals in a selected directionor directions, while suppressing the transmitted signals in otherdirections. Similarly, on the receive-side, a receiver can amplifysignals from a selected direction or directions, while suppressingunwanted signals from other directions.

The evolving 5G standard New Radio (NR) is aiming to operate in a widerange of frequencies from below 1 GHz up to 100 GHz. In NR, beam failurerecovery (BFR) is used to enable quick recovery from a beam failure.Beam failure may occur for different reasons, such as a sudden blockingof a DL beam or inefficient beam management procedures.

A BFR process consists of several actions, see FIG. 1. In a firstaction, beam failure detection at the UE is done in layer one (L1) whene.g. a block error rate (BLER) of a physical downlink control channel(PDCCH) is above a threshold for a certain time. BLER is a ratio ofnumber of erroneous blocks to the total number of blocks received.

In a second action, new candidate beams are identified by measuring beamidentification reference symbols or signals, such as channel stateinformation—reference signal (CSI-RS) which are above a threshold withrespect to signal strength or quality such as reference signal receivedpower (RSRP) or reference signal received quality (RSRQ), such as signalto interference plus noise ratio (SINR), on the CSI-RS.

In a third action, layer two (L2) is provided, from the L1, with the setof candidate beams and a BFR process is triggered which will initiate arandom access (RA) procedure.

Typically, this will trigger a contention free random access (CFRA)where the UE uses a dedicated preamble over a selected beam out of theset of candidate beams. In case the UE has no dedicated preamble forBFR, contention based random access (CBRA) may be used instead.

In a next action, the radio network node, referred to as gNodeB (gNB) inNR, transmits, back to the UE, a response to the BFR for e.g. confirmingallowed access.

The LTE random access procedure comes in two forms, allowing access tobe either contention-based, implying an inherent risk of collision, orcontention-free. In contention-based random access (CBRA), a preamble,also referred to as preamble sequence, is randomly chosen by the UE,which may result in that more than one UE simultaneously transmits thesame preamble, leading to a need for a subsequent contention resolutionprocess.

The CBRA procedure, shown in FIG. 2, consists of four actions:

1. Preamble transmission;2. Random access response transmission;3. Transmission of message 3 (MSG3);4. Contention resolution message.

Preamble transmission: The UE selects one of a set of sequences e.g.64-Z Physical Random Access Channel (PRACH) contention-based sequences,wherein Z is the number of sequences allocated, by the radio networknode, for contention-free preambles. The set of contention-basedsequences, also referred to as signatures, is further subdivided intotwo subgroups, so that the choice of preamble can carry one bit ofinformation relating to the amount of transmission resource needed totransmit Message 3. The broadcast system information indicates whichsequences are in each of the two subgroups, each subgroup correspondingto one value of the one bit of information, as well as the meaning ofeach subgroup. The UE selects a sequence from the subgroup correspondingto a size of transmission resource needed for the appropriate RandomAccess Channel (RACH) use case. It should be noted that some use casesrequire only a few bits to be transmitted in MSG3, so choosing the smallmessage size avoids allocating unnecessary uplink resources, such astime and/or frequency.

Random Access Response (RAR) transmission: The RAR conveys the identityof the detected preamble called random access preamble identity (RAPID),a timing alignment instruction to synchronize subsequent uplinktransmissions from the UE, an initial uplink resource grant fortransmission of the Step 3 message, and an assignment of a temporaryCell Radio Network Temporary Identifier (T-C-RNTI), which may or may notbe made permanent as a result of the next step called contentionresolution. The RAR may also be scrambled with a Random access RadioNetwork Temporary Identifier (RA-RNTI) when the RAR was detected andindicates the PRACH resource when the preamble was transmitted. The UEexpects to receive the RAR within a time window, of which time windowthe start and end are configured by the radio network node and broadcastas part of the cell-specific system information (SI). If the UE does notreceive a RAR within the configured time window, it selects anothersequence or preamble to be transmitted again.

Message 3 transmission: This message is the first scheduled uplinktransmission on the Physical Uplink Shared Channel (PUSCH) and makes useof Hybrid Automatic Repeat Request (HARQ). It is addressed to theT-C-RNTI allocated in the RAR. In case of a preamble collision havingoccurred at Step 1, the colliding UEs will receive the same T-C-RNTIthrough the RAR and will also collide in the same uplink time-frequencyresources when transmitting their layer 2 (L2) and/or layer 3 (L3)messages. This may result in such interference that no transmissionsfrom colliding UEs can be decoded, and the UEs restart the random accessprocedure after reaching the maximum number of HARQ retransmissions.However, if a transmission of one UE is successfully decoded, thecontention remains unresolved for the other UEs. The following downlinkmessage, in Step 4, allows a quick resolution of this contention.

Contention-resolution: The contention resolution message uses HARQ. Itis addressed to a cell-RNTI (C-RNTI), if indicated in the MSG.3 message,or to the T-C-RNTI, and, in the latter case, echoes the UE identitycontained in MSG.3. In case of a collision followed by successfuldecoding of the MSG.3, the HARQ feedback is transmitted only by the UEwhich detects its own UE identity (or C-RNTI); other UEs understandthere was a collision, transmit no HARQ feedback, and can quickly exitthe current random access procedure and start another one.

The RAR format is specified for e.g. NR in the following manner. Asspecified in the medium access control (MAC) spec TS 38.321 v15.0.0, aMAC protocol data unit (PDU) consists of one or more MAC subPDUs andoptionally padding. Each MAC subPDU comprises one of the following:

-   -   a MAC subheader with Backoff Indicator (BI) only;    -   a MAC subheader with RAPID only (i.e. acknowledgment for SI        request); and    -   a MAC subheader with RAPID and MAC RAR.

A MAC subheader with Backoff Indicator consists of five header fieldsE/T/R/R/BI as described in FIG. 3. The E field indicates an extensionfield indicating whether there is another field following the subheaderor not, the R field indicates a reserved field indicating that it doesnot have any special meaning for now, and the T field indicates a typefield which may be a flag indicating whether the MAC subheader containsa random access preamble identity or a Backoff Indicator. A MAC subPDUwith Backoff Indicator only is placed at the beginning of the MAC PDU,if included. ‘MAC subPDU(s) with RAPID only’ and ‘MAC subPDU(s) withRAPID and MAC RAR’ can be placed anywhere between MAC subPDU withBackoff Indicator only, if any, and padding, if any.

A MAC subheader with RAPID consists of three header fields E/T/RAPID asdescribed in FIG. 4.

Padding is placed at the end of the MAC PDU if present. Presence andlength of padding is implicitly based on transport block (TB) size, sizeof MAC subPDU(s).

FIG. 5 shows an example of a MAC PDU consisting of MAC subPDUs withRAPID and MAC RARs.

The MAC RAR is of a fixed size as depicted in FIG. 6, and consists ofthe following fields:

-   -   Timing Advance Command (TAC): The Timing Advance Command field        indicates an index value TA used to control the amount of timing        adjustment that the MAC entity has to apply in TS 38.213 [6].        The size of the Timing Advance Command field is 12 bits;    -   UL Grant: The Uplink (UL) Grant field indicates the resources to        be used on the uplink in e.g. TS 38.213 [6]. The size of the UL        Grant field is 20 bits;    -   Temporary C-RNTI: The Temporary C-RNTI field indicates the        temporary identity that is used by the MAC entity during Random        Access. The size of the Temporary C-RNTI field is 16 bits.

The MAC RAR is octet aligned as shown in FIG. 6.

The current RAR message comprising information such as timing advancecommand, the UL grant, and the temporary C-RNTI works in this case whenthe network receives a BFR. Upon reception of a CBRA based BFR, as abaseline option, the radio network node replies with an ordinary RARcarrying RAPID, timing advance command, the grant and the temporaryC-RNTI.

SUMMARY

It is not efficient in terms of MAC overhead using the current RAR. Anobject of embodiments herein is to provide a mechanism that efficientlyhandles communication such as a random access procedure of a UE in awireless communication network.

According to an aspect the object is achieved by providing a methodperformed by a user equipment, UE, for handling communication in awireless communication network. The UE is in a connected mode connectedto a radio network node. The UE detects a beam failure (BF) of a firstbeam and transmits, to the radio network node, a preamble of a randomaccess procedure in a second beam, wherein the preamble or a randomaccess resource used for the preamble is associated with a beam failurerecovery (BFR). The UE receives a random access response, RAR, from theradio network node, wherein the RAR comprises an UL grant and is lackinga temporary identity that is used by a medium access control (MAC)entity during a random access procedure e.g. a T-C-RNTI i.e. the RAR iswithout a T-C-RNTI.

According to another aspect the object is achieved by providing a methodperformed by a radio network node for handling communication of a UE ina wireless communication network. The UE is in a connected modeconnected to the radio network node. The radio network node receives apreamble of a random access procedure, wherein the preamble isassociated with a BFR. The radio network node transmits a random accessresponse, which random access response comprises at least an uplink, UL,grant and lacks a temporary identity that is used by a MAC entity duringa random access procedure e.g. a T-C-RNTI i.e. the radio network nodeomits adding the T-C-RNTI to the RAR. This is thus performed when thepreamble is associated with a beam failure recovery process. E.g. theradio network node receives a preamble from the UE. From said preamble,or resources carrying the preamble, the radio network node may determinethat the preamble is for BFR and to omit adding the temporary identityand add at least the UL grant into the RAR and then the radio networknode transmits the RAR to the UE. To identify that the preamble of therandom access is for a BFR, a special set of random access resourcese.g. PRACH resources, such as preamble, time and/or frequency resources,may be used for the random access procedure. The random access resourcesused for the RA procedure associated with the BFR process may bedifferent than random access resources used for a random accessprocedure related to other reasons. In this way the radio network nodemay deduce if the RA is for BFR or for something else. Since the UE isin connected mode the timing may be aligned already and the UE has aC-RNTI so the UE will not need the T-C-RNTI.

It is furthermore provided herein a computer program product comprisinginstructions, which, when executed on at least one processor, cause theat least one processor to carry out any of the methods above, asperformed by the radio network node or the UE, respectively. It isadditionally provided herein a computer-readable storage medium, havingstored thereon a computer program product comprising instructions which,when executed on at least one processor, cause the at least oneprocessor to carry out the method according to any of the methods above,as performed by the radio network node or the UE, respectively.

According to still another aspect the object is achieved by providing auser equipment for handling communication in a wireless communicationnetwork. The user equipment is configured to detect a BF of a first beamwhen the UE is in connected mode being connected to a radio networknode. The UE is further configured to transmit, to the radio networknode, a preamble of a random access procedure in a second beam, whereinthe preamble or a random access resource used for the preamble isassociated with a beam failure recovery. The UE is also configured toreceive a RAR from the radio network node, wherein the RAR comprises anUL grant and is lacking a temporary identity that is used by a MACentity during a random access procedure such as a T-C-RNTI e.g. the RARis without a T-C-RNTI.

According to yet another aspect the object is achieved by providing aradio network node for handling communication of a UE in a wirelesscommunication network. The radio network node is configured to receive,from the UE being in a connected mode, of a first beam, connected to theradio network node, a preamble of a random access procedure of a secondbeam, wherein the preamble or a random access resource used for thepreamble is associated with a BFR. The radio network node is furtherconfigured to transmit a random access response, which random accessresponse comprises at least an uplink, UL, grant and lacks a temporaryidentity that is used by a medium access control, MAC, entity during arandom access procedure, e.g. a temporary cell radio network temporaryidentifier, T-C-RNTI, hence the radio network node is configured to omitadding the T-C-RNTI to the RAR.

Embodiments herein describe methods used for during beam failure e.g.BFR. The UL grant may be sufficient in the case where the UE is inconnected mode which means that the UE already has a C-RNTI and thetiming is already aligned. Thus, an improved RAR format is hereindisclosed comprising: only the field of UL grant in case the UE MAC hasdetected a beam failure, e.g. while the uplink time alignment is stillbeing maintained; the field of the UL grant and the TAC field and/or abeam index field. This results in a reduced MAC overhead by not usingunnecessary fields such as T-C-RNTI field which may mean an improvednetwork coverage for RACH accesses and/or energy consumed during randomaccess (RA) signalling. Embodiments herein reduce the unnecessary MACoverhead for BFR triggered RACH access. It is especially useful for a UEin a coverage limited scenario.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described in more detail in relation to theenclosed drawings, in which:

FIG. 1 shows a schematic overview of a BFR;

FIG. 2 shows an overview of the RA procedure in LTE;

FIG. 3 is a schematic overview depicting a MAC subPDU;

FIG. 4 is a schematic overview depicting a MAC subPDU;

FIG. 5 is a schematic overview depicting a MAC PDU;

FIG. 6 is a schematic overview depicting a MAC RAR;

FIG. 7 is a schematic overview depicting a wireless communicationnetwork according to embodiments herein;

FIG. 8 shows a combined flowchart and signalling scheme according toembodiments herein;

FIG. 9A-9C show different MAC RARs according to embodiments herein;

FIG. 10 shows a schematic flowchart depicting a method performed by a UEaccording to embodiments herein;

FIG. 11 shows a schematic flowchart depicting a method performed by aradio network node according to embodiments herein;

FIG. 12 is a block diagram depicting a UE node according to embodimentsherein;

FIG. 13 is a block diagram depicting a radio network node according toembodiments herein;

FIG. 14 shows a telecommunication network connected via an intermediatenetwork to a host computer in accordance with some embodiments;

FIG. 15 shows a host computer communicating via a base station with auser equipment over a partially wireless connection in accordance withsome embodiments;

FIG. 16 shows methods implemented in a communication system including ahost computer, a base station and a user equipment in accordance withsome embodiments;

FIG. 17 shows methods implemented in a communication system including ahost computer, a base station and a user equipment in accordance withsome embodiments;

FIG. 18 shows methods implemented in a communication system including ahost computer, a base station and a user equipment in accordance withsome embodiments; and

FIG. 19 shows methods implemented in a communication system including ahost computer, a base station and a user equipment in accordance withsome embodiments.

DETAILED DESCRIPTION

Embodiments herein relate to wireless communication networks in general.FIG. 7 is a schematic overview depicting a wireless communicationnetwork 1. The wireless communication network 1 comprises one or moreRANs and one or more CNs. The wireless communication network 1 may useone or a number of different technologies. Embodiments herein relate torecent technology trends that are of particular interest in a 5Gcontext; however, embodiments are also applicable in further developmentof existing wireless communication systems such as e.g. Wideband CodeDivision Multiple Access (WCDMA) and LTE.

In the wireless communication network 1, UEs e.g. a UE 10 such as amobile station, a non-access point (non-AP) STA, a STA, a user equipmentand/or a wireless terminal, communicate via one or more Access Networks(AN), e.g. RAN, to one or more core networks (CN). It should beunderstood by the skilled in the art that “UE” is a non-limiting termwhich means any terminal, wireless communication terminal, userequipment, Machine Type Communication (MTC) device, Device to Device(D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor,relay, mobile tablets or even a small base station capable ofcommunicating using radio communication with a radio network node withinan area served by the radio network node.

The wireless communication network 1 comprises a radio network node 12providing radio coverage over a geographical area, a first service area11, of a first radio access technology (RAT), such as NR, LTE, orsimilar. The radio network node 12 may be a transmission and receptionpoint e.g. a radio network node such as a Wireless Local Area Network(WLAN) access point or an Access Point Station (AP STA), an access node,an access controller, a base station, e.g. a radio base station such asa gNodeB (gNB), an evolved Node B (eNB, eNode B), a base transceiverstation, a radio remote unit, an Access Point Base Station, a basestation router, a transmission arrangement of a radio base station, astand-alone access point or any other network unit or node capable ofcommunicating with a UE within the area served by the radio network node12 depending e.g. on the first radio access technology and terminologyused. The radio network node 12 may alternatively or additionally be acontroller node or a packet processing node such as a radio controllernode or similar. The radio network node may be referred to as a servingradio network node wherein the first service may be referred to as aserving cell, and the serving network node communicates with the UE 10in form of DL transmissions to the UE 10 and UL transmissions from theUE 10. It should be noted that a service area may be denoted as cell,beam, beam group or similar to define an area of radio coverage. Theradio network node 12 transmits reference signals, such as SSBs orchannel state information reference signal (CSI-RS), over the servicearea. Each SSB or CSI-RS being associated with a beam e.g. each SSB orCSI-RS is representing a respective beam. Hence, the radio network node12, 13 transmits SSBs or CSI-RSs repeatedly, in time, in a large numberof different directions using e.g. as many transmission-beams as deemednecessary to cover an operational area of the respective radio networknode.

According to embodiments herein the UE 10 is in a connected mode, i.e.the UE 10 may be radio resource control (RRC) connected e.g. has a RRCconnection, with the radio network node 12. The UE 10 detects a BF e.g.a signal strength of a signal of a first beam is below a set threshold.The UE 10 then transmits a preamble of a random access procedure in asecond beam, wherein the preamble or a random access resource used forthe preamble is associated with a BFR, e.g. the transmission of thepreamble uses random access resources such as frequency and/or time (ora preamble) allocated for random access for a BFR. The radio networknode 12 receives the preamble and detects that the preamble isassociated with a BFR. The radio network node 12 then transmits a RARcomprising at least an UL grant and lacking a temporary identity that isused by a MAC entity during a random access procedure such as aT-C-RNTI. Since the UE 10 was in connected mode it is sufficient withthe UL grant in the RAR for the UE 10 to be able to use the second beamfor transmissions. Hence, the overhead of the RAR is reduced and radioresources used as well as energy consumption are reduced.

FIG. 8 is a combined flowchart and signalling scheme according toembodiments herein.

Action 801. The radio network node 12 may configure the UE 10 bytransmitting configuration data indicating the configuration of the RARto the UE 10 via e.g. Radio Resource Control (RRC) messages. Theconfiguration data may indicate whether to use an ordinary RAR format,which carries fields such as Timing Advance Command, UL grant andTemporary C-RNTI, or a different RAR format disclosed herein for arandom access procedure associated with a BFR. The configuration datamay comprise one or more random access resources such as preamble, timeand/or frequency for a BFR. The one or more random access resources mayalso be preconfigured at the UE 10. The configuration of the RAR may besignalled in system information and/or signalled/updated via a MACControl Element (CE), PDCCH command or other L1/L2 signallingalternatives.

Action 802. The UE 10 detects a beam failure of the first beam. E.g. theUE detection may be done in L1 when e.g. a BLER of the PDCCH is above athreshold for e.g. a pre-set time.

Action 803. The UE 10 may then initiate a BFR. E.g. the UE 10 may selecta second beam to perform BFR on. The second beam may be selected basedon signal strength and/or quality. The second beam may thus beidentified by measuring beam identification reference symbols or signals(RS), such as CSI-RS, which are above a threshold with respect to signalstrength or quality such as RSRP or RSRQ, such as SINR, on the RS.

Action 804. The UE 10 transmits a preamble in the second beam, beingdifferent than the first beam, during a random access procedure for thesecond beam. The preamble or a random access resource, such as time andfrequency, used for the preamble is associated with a beam failurerecovery e.g. since these may be allocated for BFR processes.

Action 805. The network node 12 identifies the random access procedureas a random access procedure for a BFR process and responds to the UE 10with the RAR. The RAR carries the UL grant and/or timing advance commandbut lacks at least the temporary identity such as a T-C-RNTI.

Action 806. The UE 10 may then determine that the RAR is intended forthe UE based on e.g. RAPID or RA-RNTI in the RAR.

Action 807. The UE may then transmit a message, e.g. message 3, to theradio network node 12 in the second beam according to the UL grant inthe RAR. This message is a first scheduled uplink transmission on thePUSCH and may make use of HARQ.

Action 808. The transmission of the UE 10 may then successfully bedecoded at the radio network node 12.

FIG. 9A discloses one embodiment out of a number of various embodimentsfor the MAC RAR. The radio network node 12 may, as a Random accessresponse for a BFR triggered random access procedure, transmit a MAC PDUcomprising one or more MAC subPDUs and optionally padding. Each MACsubPDU may comprise one of the following:

-   -   a MAC subheader with Backoff Indicator only;    -   a MAC subheader with RAPID only, i.e. acknowledgment for SI        request; and    -   a MAC subheader with RAPID and MAC RAR.

According to embodiments herein the MAC RAR has an improved formatcomprising e.g. only the field of UL grant, which may have a size of 20bits. This improved format is applied in case the UE 10 has detected abeam failure of the first beam, while the uplink time alignment is stillbeing maintained since the UE is in connected state.

Alternatively, the RAR format according to embodiments herein maycomprise fields including Timing Advance Command, and UL grant, see FIG.9B. This format may be applied in case the UE has detected a beamfailure, while the uplink time alignment is also lost. This may beindicated in the preamble transmission.

Alternatively or additionally, besides the fields that are described inthe above embodiments, the RAR format may comprise an additional fieldindicating beam index, wherein the additional field indicates the indexfor a new serving beam that the radio network node 12 may assign to theUE 10 see FIG. 9C. The additional field may be 6-8 bits. The radionetwork node 12 may configure the UE 10 whether to use the ordinary RARformat, which carries fields Timing Advance Command, UL grant andTemporary C-RNTI, or the improved RAR format. The configuration on theRAR format may be signalled to the UE 10, by the radio network node 12,via system information or dedicated RRC signalling.

The method actions performed by the UE 10 for handling communication,e.g. performing access related process or similar, in the wirelesscommunication network 1 according to embodiments will now be describedwith reference to a flowchart depicted in FIG. 10. The actions do nothave to be taken in the order stated below, but may be taken in anysuitable order. Actions performed in some embodiments are marked withdashed boxes. The UE 10 is in a connected mode in the first beamconnected to the radio network node 12. E.g. the UE 10 is connected tothe radio network node e.g. RRC connected and using the first beam.

Action 1000. The UE 10 may receive configuration data from the radionetwork node 12, configuring the UE 10 to use a RAR format withtemporary identifier or not upon beam failure.

Action 1001. The UE 10 detects the BF of the first beam.

Action 1002. The UE 10 may select the second beam e.g. based on measuredsignal strength or quality of candidate beams.

Action 1003. The UE 10 transmits, to the radio network node 12, apreamble of a random access procedure in the second beam, wherein thepreamble or the random access resource used for the preamble isassociated with a BFR. The preamble or the random access resource usedfor the preamble may be associated with the beam failure recovery inthat the preamble may be of the set of predetermined preambles or therandom access resource, used when transmitting the preamble, is of theset of predetermined random access resources. Thus, the preamble or arandom access resource may be preconfigured for BFR.

Action 1004. The UE 10 receives the RAR, from the radio network node 12,wherein the RAR comprises the UL grant but without a temporary identitythat is used by a MAC entity during a random access procedure. Thus theRAR may comprise an UL grant and is lacking e.g. a temporary C-RNTI i.e.the RAR is without a T-C-RNTI. The RAR may further lack timing advancecommand. Since the UE 10 is in connected mode the UE 10 may use RA-RNTIto determine that the RAR is intended for the UE 10. Thus, RA-RNTI isdetermined by the preamble or PRACH resource where preamble was sent andthe UE already has C-RNTI since it is in connected mode, sent in an msg3from UE 10 to radio network node 12 in e.g. first beam. Thus, the UE 10may already have a first temporary identity associated to random accesssent in a message in the first beam. The RAR may thus comprise only theUL grant, the UL grant and a timing advance command, and/or a beam indexof the second beam but without the temporary identity.

Action 1005. The UE 10 may then transmit a message, such as message 3,to the radio network node 12. This message may be a first scheduleduplink transmission on e.g. the PUSCH as indicated by the UL grant.

The method actions performed by the radio network node 12 for handlingcommunication of the UE 10, e.g. handling access procedure from the UE10, in the wireless communication network 1 according to someembodiments will now be described with reference to a flowchart depictedin FIG. 11. The actions do not have to be taken in the order statedbelow, but may be taken in any suitable order. Actions performed in someembodiments are marked with dashed boxes. The UE 10 is in a connectedmode, of the first beam, connected to the radio network node 12.

Action 1100. The radio network node 12 may transmit configuration datato the UE (10), configuring the UE to use a RAR format with temporaryidentifier or not

Action 1101. The radio network node 12 receives the preamble from the UE10 of a random access procedure of the second beam. The preamble mayindicate the second beam. Furthermore, the preamble or the random accessresource used for the preamble is associated with a BFR. E.g. the randomaccess resource used for the transmission such as the preamble, thefrequency and/or the time, are allocated for random access proceduresfor a BFR. Thus, the radio network node 12 may detect that the randomaccess procedure or the preamble is associated with a BFR e.g. based onrandom access resources used or preamble used. E.g. the radio networknode 12 may detect that the preamble is associated with the BFR bydetecting that the preamble is of the set of predetermined preambles orthe random access resource, used when transmitting the preamble, is ofthe set of predetermined random access resources.

Action 1102. The radio network node 12 then transmits the RAR, whereinthe RAR comprises at least the UL grant and lacks the temporary identitythat is used by the MAC entity during a random access procedure. E.g.the RAR comprises the UL grant and is lacking a T-C-RNTI. The RAR maycomprise: only the UL grant, the UL grant and a timing advance command;and/or a beam index of the second beam but without the temporaryidentity. The UE 10 may already have a temporary identity associated torandom access sent in a message in the first beam. The radio networknode 12 may, in response to detecting that the preamble is associatedwith the BFR, omitting adding the temporary identifier to the RAR.

Action 1103. The radio network node 12 may then receive a message, e.g.a message 3, from the UE 10. The message 3 is addressed to the temporaryC-RNTI allocated in the RAR.

FIG. 12 is a block diagram depicting the UE 10 for handlingcommunication in the wireless communication network according toembodiments herein.

The UE may comprise processing circuitry 1201, such as one or moreprocessors, configured to perform methods herein.

The UE 10 may comprise a detecting unit 1202. The UE 10, the processingcircuitry 1201, and/or the detecting unit 1202 is configured to detect abeam failure in a first beam.

The UE 10 may comprise a transmitting unit 1203, e.g. a transmitter or atransceiver. The UE, the processing circuitry 1201, and/or thetransmitting unit 1203 is configured to, upon being in a connected modeto the radio network node 12, transmit the preamble in the second beamto the radio network node 12.

The UE 10 may comprise a receiving unit 1204, e.g. a receiver or atransceiver. The UE 10, the processing circuitry 1201, and/or thereceiving unit 1204 is configured to receive the RAR from the radionetwork node 12, wherein the RAR comprises at least the UL grant andlacks a T-C-RNTI.

The UE 10 may comprise a selecting unit 1205. The UE 10, the processingcircuitry 1201, and/or the selecting unit 1205 may be configured toselect the second beam.

The UE 10 further comprises a memory 1206. The memory comprises one ormore units to be used to store data on, such as signal strengths orqualities, IDs of radio network nodes, preambles, RAR information,applications to perform the methods disclosed herein when beingexecuted, and similar.

The UE 10 may further comprise a communication interface such astransmitter, receiver, transceiver and/or one or more antennas.

The methods according to the embodiments described herein for the UE 10are respectively implemented by means of e.g. a computer program product1207 or a computer program, comprising instructions, i.e., software codeportions, which, when executed on at least one processor, cause the atleast one processor to carry out the actions described herein, asperformed by the UE 10. The computer program product 1207 may be storedon a computer-readable storage medium 1208, e.g. a disc, a universalserial bus (USB) stick or similar. The computer-readable storage medium1208, having stored thereon the computer program product, may comprisethe instructions which, when executed on at least one processor, causethe at least one processor to carry out the actions described herein, asperformed by the UE 10. In some embodiments, the computer-readablestorage medium may be a transitory or a non-transitory computer-readablestorage medium. Thus, the UE 10 may comprise the processing circuitryand the memory, said memory comprising instructions executable by saidprocessing circuitry whereby said UE is operative to perform the methodsherein.

FIG. 13 is a block diagram depicting the radio network node 12 such as agNodeB (gNB), for handling communication of the UE 10 in the wirelesscommunication network according to embodiments herein.

The radio network node 12 may comprise processing circuitry 1301, e.g.one or more processors, configured to perform the methods herein.

The radio network node 12 may comprise a receiving unit 1302, a receiveror a transceiver. The radio network node 12, the processing circuitry1301, and/or the receiving unit 1302 is configured to receive thepreamble from the UE 10.

The radio network node 12 may comprise a transmitting unit 1303, e.g. atransmitter or the transceiver. The radio network node 12, theprocessing circuitry 1301, and/or the transmitting unit 1303 isconfigured to transmit the RAR to the UE 10, wherein the RAR comprise atleast UL grant. For example, the RAR such as the MAC RAR may compriseonly the UL grant, or the RAR may comprise only UL grant and timingadvance command and/or a beam index of the second beam.

The radio network node 12 may comprise a detecting unit 1304. The radionetwork node 12, the processing circuitry 1301, and/or the detectingunit 1304 may be configured to detect that the preamble or the randomaccess procedure of the preamble is for a BFR process.

The radio network node 12 further comprises a memory 1305. The memorycomprises one or more units to be used to store data on, such as signalstrengths or qualities, IDs of radio network nodes, preambles, RARinformation, applications to perform the methods disclosed herein whenbeing executed, and similar.

The radio network node 12 may further comprise a communication interfacesuch as transmitter, receiver, transceiver and/or one or more antennas.

The methods according to the embodiments described herein for the radionetwork node 12 may be respectively implemented by means of e.g. acomputer program product 1306 or a computer program, comprisinginstructions, i.e., software code portions, which, when executed on atleast one processor, cause the at least one processor to carry out theactions described herein, as performed by the radio network node 12. Thecomputer program product 1306 may be stored on a computer-readablestorage medium 1307, e.g. a disc, a universal serial bus (USB) stick orsimilar. The computer-readable storage medium 1307, having storedthereon the computer program product, may comprise the instructionswhich, when executed on at least one processor, cause the at least oneprocessor to carry out the actions described herein, as performed by theradio network node 12. In some embodiments, the computer-readablestorage medium may be a transitory or a non-transitory computer-readablestorage medium. Thus, the radio network node 12 may comprise theprocessing circuitry and the memory, said memory comprising instructionsexecutable by said processing circuitry whereby said radio network nodeis operative to perform the methods herein.

In some embodiments a more general term “radio network node” is used andit can correspond to any type of radio-network node or any network node,which communicates with a UE and/or with another network node. Examplesof network nodes are NodeB, MeNB, SeNB, a network node belonging toMaster cell group (MCG) or Secondary cell group (SCG), base station(BS), multi-standard radio (MSR) radio node such as MSR BS, eNodeB,network controller, radio-network controller (RNC), base stationcontroller (BSC), relay, donor node controlling relay, base transceiverstation (BTS), access point (AP), transmission points, transmissionnodes, Remote radio Unit (RRU), Remote Radio Head (RRH), nodes indistributed antenna system (DAS), etc.

In some embodiments the non-limiting term UE or user equipment (UE) isused and it refers to any type of UE communicating with a network nodeand/or with another UE in a cellular or mobile communication system.Examples of UE are target device, device to device (D2D) UE, proximitycapable UE (aka ProSe UE), machine type UE or UE capable of machine tomachine (M2M) communication, Tablet, mobile terminals, smart phone,laptop embedded equipped (LEE), laptop mounted equipment (LME), USBdongles etc.

The embodiments are described for 5G or NR. However the embodiments areapplicable to any RAT or multi-RAT systems, where the UE receives and/ortransmit signals (e.g. data) e.g. Wi-Fi, Long Term Evolution (LTE),LTE-Advanced, Wideband Code Division Multiple Access (WCDMA), GlobalSystem for Mobile communications/enhanced Data rate for GSM Evolution(GSM/EDGE), Worldwide Interoperability for Microwave Access (WiMax), orUltra Mobile Broadband (UMB), just to mention a few possibleimplementations.

As will be readily understood by those familiar with communicationsdesign, that functions means or circuits may be implemented usingdigital logic and/or one or more microcontrollers, microprocessors, orother digital hardware. In some embodiments, several or all of thevarious functions may be implemented together, such as in a singleapplication-specific integrated circuit (ASIC), or in two or moreseparate devices with appropriate hardware and/or software interfacesbetween them. Several of the functions may be implemented on a processorshared with other functional components of a UE or network node, forexample.

Alternatively, several of the functional elements of the processingmeans discussed may be provided through the use of dedicated hardware,while others are provided with hardware for executing software, inassociation with the appropriate software or firmware. Thus, the term“processor” or “controller” as used herein does not exclusively refer tohardware capable of executing software and may implicitly include,without limitation, digital signal processor (DSP) hardware and/orprogram or application data. Other hardware, conventional and/or custom,may also be included. Designers of communications devices willappreciate the cost, performance, and maintenance trade-offs inherent inthese design choices.

With reference to FIG. 14, in accordance with an embodiment, acommunication system includes a telecommunication network 3210, such asa 3GPP-type cellular network, which comprises an access network 3211,such as a radio access network, and a core network 3214. The accessnetwork 3211 comprises a plurality of base stations 3212 a, 3212 b, 3212c, such as NBs, eNBs, gNBs or other types of wireless access pointsbeing examples of the radio network node 12 herein, each defining acorresponding coverage area 3213 a, 3213 b, 3213 c. Each base station3212 a, 3212 b, 3212 c is connectable to the core network 3214 over awired or wireless connection 3215. A first user equipment (UE) 3291,being an example of the UE 10, located in coverage area 3213 c isconfigured to wirelessly connect to, or be paged by, the correspondingbase station 3212 c. A second UE 3292 in coverage area 3213 a iswirelessly connectable to the corresponding base station 3212 a. While aplurality of UEs 3291, 3292 are illustrated in this example, thedisclosed embodiments are equally applicable to a situation where a soleUE is in the coverage area or where a sole UE is connecting to thecorresponding base station 3212.

The telecommunication network 3210 is itself connected to a hostcomputer 3230, which may be embodied in the hardware and/or software ofa standalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. The host computer 3230 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider. Theconnections 3221, 3222 between the telecommunication network 3210 andthe host computer 3230 may extend directly from the core network 3214 tothe host computer 3230 or may go via an optional intermediate network3220. The intermediate network 3220 may be one of, or a combination ofmore than one of, a public, private or hosted network; the intermediatenetwork 3220, if any, may be a backbone network or the Internet; inparticular, the intermediate network 3220 may comprise two or moresub-networks (not shown).

The communication system of FIG. 14 as a whole enables connectivitybetween one of the connected UEs 3291, 3292 and the host computer 3230.The connectivity may be described as an over-the-top (OTT) connection3250. The host computer 3230 and the connected UEs 3291, 3292 areconfigured to communicate data and/or signalling via the OTT connection3250, using the access network 3211, the core network 3214, anyintermediate network 3220 and possible further infrastructure (notshown) as intermediaries. The OTT connection 3250 may be transparent inthe sense that the participating communication devices through which theOTT connection 3250 passes are unaware of routing of uplink and downlinkcommunications. For example, a base station 3212 may not or need not beinformed about the past routing of an incoming downlink communicationwith data originating from a host computer 3230 to be forwarded (e.g.,handed over) to a connected UE 3291. Similarly, the base station 3212need not be aware of the future routing of an outgoing uplinkcommunication originating from the UE 3291 towards the host computer3230.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 15. In a communicationsystem 3300, a host computer 3310 comprises hardware 3315 including acommunication interface 3316 configured to set up and maintain a wiredor wireless connection with an interface of a different communicationdevice of the communication system 3300. The host computer 3310 furthercomprises processing circuitry 3318, which may have storage and/orprocessing capabilities. In particular, the processing circuitry 3318may comprise one or more programmable processors, application-specificintegrated circuits, field programmable gate arrays or combinations ofthese (not shown) adapted to execute instructions. The host computer3310 further comprises software 3311, which is stored in or accessibleby the host computer 3310 and executable by the processing circuitry3318. The software 3311 includes a host application 3312. The hostapplication 3312 may be operable to provide a service to a remote user,such as a UE 3330 connecting via an OTT connection 3350 terminating atthe UE 3330 and the host computer 3310. In providing the service to theremote user, the host application 3312 may provide user data which istransmitted using the OTT connection 3350.

The communication system 3300 further includes a base station 3320provided in a telecommunication system and comprising hardware 3325enabling it to communicate with the host computer 3310 and with the UE3330. The hardware 3325 may include a communication interface 3326 forsetting up and maintaining a wired or wireless connection with aninterface of a different communication device of the communicationsystem 3300, as well as a radio interface 3327 for setting up andmaintaining at least a wireless connection 3370 with a UE 3330 locatedin a coverage area (not shown in FIG. 15) served by the base station3320. The communication interface 3326 may be configured to facilitate aconnection 3360 to the host computer 3310. The connection 3360 may bedirect or it may pass through a core network (not shown in FIG. 15) ofthe telecommunication system and/or through one or more intermediatenetworks outside the telecommunication system. In the embodiment shown,the hardware 3325 of the base station 3320 further includes processingcircuitry 3328, which may comprise one or more programmable processors,application-specific integrated circuits, field programmable gate arraysor combinations of these (not shown) adapted to execute instructions.The base station 3320 further has software 3321 stored internally oraccessible via an external connection.

The communication system 3300 further includes the UE 3330 alreadyreferred to. Its hardware 3335 may include a radio interface 3337configured to set up and maintain a wireless connection 3370 with a basestation serving a coverage area in which the UE 3330 is currentlylocated. The hardware 3335 of the UE 3330 further includes processingcircuitry 3338, which may comprise one or more programmable processors,application-specific integrated circuits, field programmable gate arraysor combinations of these (not shown) adapted to execute instructions.The UE 3330 further comprises software 3331, which is stored in oraccessible by the UE 3330 and executable by the processing circuitry3338. The software 3331 includes a client application 3332. The clientapplication 3332 may be operable to provide a service to a human ornon-human user via the UE 3330, with the support of the host computer3310. In the host computer 3310, an executing host application 3312 maycommunicate with the executing client application 3332 via the OTTconnection 3350 terminating at the UE 3330 and the host computer 3310.In providing the service to the user, the client application 3332 mayreceive request data from the host application 3312 and provide userdata in response to the request data. The OTT connection 3350 maytransfer both the request data and the user data. The client application3332 may interact with the user to generate the user data that itprovides.

It is noted that the host computer 3310, base station 3320 and UE 3330illustrated in FIG. 15 may be identical to the host computer 3230, oneof the base stations 3212 a, 3212 b, 3212 c and one of the UEs 3291,3292 of FIG. 14, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 15 and independently, thesurrounding network topology may be that of FIG. 14.

In FIG. 15, the OTT connection 3350 has been drawn abstractly toillustrate the communication between the host computer 3310 and the userequipment 3330 via the base station 3320, without explicit reference toany intermediary devices and the precise routing of messages via thesedevices. Network infrastructure may determine the routing, which it maybe configured to hide from the UE 3330 or from the service provideroperating the host computer 3310, or both. While the OTT connection 3350is active, the network infrastructure may further take decisions bywhich it dynamically changes the routing (e.g., on the basis of loadbalancing consideration or reconfiguration of the network).

The wireless connection 3370 between the UE 3330 and the base station3320 is in accordance with the teachings of the embodiments describedthroughout this disclosure. One or more of the various embodimentsimprove the performance of OTT services provided to the UE 3330 usingthe OTT connection 3350, in which the wireless connection 3370 forms thelast segment. More precisely, the teachings of these embodiments mayimprove the latency since the RAR uses a reduced overhead and otherservices may use the resources and thereby provide benefits such asreduced waiting time and better responsiveness.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring the OTT connection 3350 between the hostcomputer 3310 and UE 3330, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring the OTT connection 3350 may be implemented in the software3311 of the host computer 3310 or in the software 3331 of the UE 3330,or both. In embodiments, sensors (not shown) may be deployed in or inassociation with communication devices through which the OTT connection3350 passes; the sensors may participate in the measurement procedure bysupplying values of the monitored quantities exemplified above, orsupplying values of other physical quantities from which software 3311,3331 may compute or estimate the monitored quantities. The reconfiguringof the OTT connection 3350 may include message format, retransmissionsettings, preferred routing etc.; the reconfiguring need not affect thebase station 3320, and it may be unknown or imperceptible to the basestation 3320. Such procedures and functionalities may be known andpracticed in the art. In certain embodiments, measurements may involveproprietary UE signalling facilitating the host computer's 3310measurements of throughput, propagation times, latency and the like. Themeasurements may be implemented in that the software 3311, 3331 causesmessages to be transmitted, in particular empty or ‘dummy’ messages,using the OTT connection 3350 while it monitors propagation times,errors etc.

FIG. 16 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 14 and 15. Forsimplicity of the present disclosure, only drawing references to FIG. 16will be included in this section. In a first step 3410 of the method,the host computer provides user data. In an optional substep 3411 of thefirst step 3410, the host computer provides the user data by executing ahost application. In a second step 3420, the host computer initiates atransmission carrying the user data to the UE. In an optional third step3430, the base station transmits to the UE the user data which wascarried in the transmission that the host computer initiated, inaccordance with the teachings of the embodiments described throughoutthis disclosure. In an optional fourth step 3440, the UE executes aclient application associated with the host application executed by thehost computer.

FIG. 17 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 14 and 15. Forsimplicity of the present disclosure, only drawing references to FIG. 17will be included in this section. In a first step 3510 of the method,the host computer provides user data. In an optional substep (not shown)the host computer provides the user data by executing a hostapplication. In a second step 3520, the host computer initiates atransmission carrying the user data to the UE. The transmission may passvia the base station, in accordance with the teachings of theembodiments described throughout this disclosure. In an optional thirdstep 3530, the UE receives the user data carried in the transmission.

FIG. 18 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 14 and 15. Forsimplicity of the present disclosure, only drawing references to FIG. 18will be included in this section. In an optional first step 3610 of themethod, the UE receives input data provided by the host computer.Additionally or alternatively, in an optional second step 3620, the UEprovides user data. In an optional substep 3621 of the second step 3620,the UE provides the user data by executing a client application. In afurther optional substep 3611 of the first step 3610, the UE executes aclient application which provides the user data in reaction to thereceived input data provided by the host computer. In providing the userdata, the executed client application may further consider user inputreceived from the user. Regardless of the specific manner in which theuser data was provided, the UE initiates, in an optional third substep3630, transmission of the user data to the host computer. In a fourthstep 3640 of the method, the host computer receives the user datatransmitted from the UE, in accordance with the teachings of theembodiments described throughout this disclosure.

FIG. 19 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 14 and 15. Forsimplicity of the present disclosure, only drawing references to FIG. 19will be included in this section. In an optional first step 3710 of themethod, in accordance with the teachings of the embodiments describedthroughout this disclosure, the base station receives user data from theUE. In an optional second step 3720, the base station initiatestransmission of the received user data to the host computer. In a thirdstep 3730, the host computer receives the user data carried in thetransmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional unitsor modules of one or more virtual apparatuses. Each virtual apparatusmay comprise a number of these functional units. These functional unitsmay be implemented via processing circuitry, which may include one ormore microprocessor or microcontrollers, as well as other digitalhardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

It will be appreciated that the foregoing description and theaccompanying drawings represent non-limiting examples of the methods andapparatus taught herein. As such, the apparatus and techniques taughtherein are not limited by the foregoing description and accompanyingdrawings. Instead, the embodiments herein are limited only by thefollowing claims and their legal equivalents.

1. A method performed by a user equipment, UE, for handlingcommunication in a wireless communication network, the UE being in aconnected mode in a first beam connected to a radio network node, themethod comprising: detecting a beam failure of the first beam;transmitting, to the radio network node, a preamble of a random accessprocedure in a second beam, one of the preamble and a random accessresource used for the preamble being associated with a beam failurerecovery; and receiving a random access response, RAR, from the radionetwork node, the RAR comprising an uplink, UL, grant but without atemporary identity that is used by a medium access control, MAC, entityduring a random access procedure.
 2. The method according to claim 1,wherein one of: the RAR comprises only the UL grant; and the RARcomprises at least one selected from the group consisting of the ULgrant and a timing advance command and a beam index of the second beambut without the temporary identity.
 3. The method according to claim 1,further comprising: selecting the second beam.
 4. The method accordingto claim 1, wherein the UE already has a first temporary identityassociated to random access sent in a message in the first beam.
 5. Themethod according to claim 1, wherein the one of the preamble and therandom access resource used for the preamble is associated with the beamfailure recovery in that the preamble is of a set of predeterminedpreambles or the random access resource, used when transmitting thepreamble, is of a set of predetermined random access resources.
 6. Themethod according to claim 1, further comprising: receiving configurationdata from the radio network node, configuring the UE to one of use andnot use a RAR format with temporary identifier upon beam failure.
 7. Amethod performed by a radio network node for handling communication of aUE in a wireless communication network, the UE being in a connectedmode, of a first beam, connected to the radio network node, the methodcomprising: receiving a preamble of a random access procedure of asecond beam, one of the preamble and a random access resource used forthe preamble being associated with a beam failure recovery, BFR; andtransmitting a random access response, RAR, the RAR comprising at leastan uplink, UL, grant and lacking a temporary identity that is used by amedium access control, MAC, entity during a random access procedure. 8.The method according to claim 7, wherein one of: the RAR comprises onlythe UL grant; and the RAR comprises at least one selected from the groupconsisting of the UL grant and a timing advance command and a beam indexof the second beam but without the temporary identity.
 9. The methodaccording to claim 7, wherein the UE already has a temporary identityassociated to random access sent in a message in the first beam.
 10. Themethod according to claim 7, further comprising: transmittingconfiguration data to the UE, configuring the UE to one of use and notuse a RAR format with temporary identifier.
 11. The method according toclaim 7, wherein receiving the preamble of the second beam comprisesdetecting that the preamble is associated with the BFR.
 12. The methodaccording to claim 11, wherein detecting that the preamble is associatedwith the BFR by detecting one of that the preamble is of a set ofpredetermined preambles and the random access resource, used whentransmitting the preamble, is of a set of predetermined random accessresources.
 13. The method according to claim 11, wherein transmittingthe RAR further comprises, in response to detecting that the preamble isassociated with the BFR, omitting adding the temporary identifier to theRAR.
 14. A user equipment, UE, for handling communication in a wirelesscommunication network, wherein the UE is configured to: detect a beamfailure of a first beam, the UE is being in a connected mode in thefirst beam connected to a radio network node; transmit, to the radionetwork node, a preamble of a random access procedure in a second beam,one of the preamble and a random access resource used for the preamblebeing associated with a beam failure recovery; and receive a randomaccess response, RAR, from the radio network node, the RAR comprising anuplink, UL, grant but without a temporary identity that is used by amedium access control, MAC, entity during a random access procedure. 15.The UE according to claim 14, wherein one of: the RAR comprises only theUL grant; and the RAR comprises at least one selected from the groupconsisting of the UL grant and a timing advance command and/or and abeam index of the second beam but without the temporary identity. 16.The UE according to claim 14, wherein the UE is further configured toselect the second beam.
 17. The UE according to claim 14, wherein the UEalready has a first temporary identity associated to random access sentin a message in the first beam.
 18. The UE according to claim 14,wherein the one of the preamble and the random access resource used forthe preamble is associated with the beam failure recovery in that thepreamble is of a set of predetermined preambles or the random accessresource, used when transmitting the preamble, is of a set ofpredetermined random access resources.
 19. The UE according to claim 14,wherein the UE is further configured to receive configuration from theradio network node, configuring the UE to one of use and not use a RARformat with temporary identifier or not upon beam failure.
 20. A radionetwork node for handling communication of a UE in a wirelesscommunication network, the radio network node is being configured to:receive, from the UE being in a connected mode, of a first beam,connected to the radio network node, a preamble of a random accessprocedure of a second beam, one of the preamble and a random accessresource used for the preamble being associated with a beam failurerecovery, BFR; and transmit a random access response, RAR, to the UE,the RAR comprising at least an uplink, UL, grant and lacking a temporaryidentity that is used by a medium access control, MAC, entity during arandom access procedure.
 21. The radio network node according to claim20, wherein one of: the RAR comprises only the UL grant; and the RARcomprises at least one selected from the group consisting of the ULgrant and a timing advance command and a beam index of the second beambut without the temporary identity.
 22. The radio network node accordingto claim 20, wherein the UE already has a temporary identity associatedto random access sent in a message in the first beam.
 23. The radionetwork node according to claim 20, wherein the radio network node isfurther configured to transmit configuration to the UE, configuring theUE to use a RAR format with temporary identifier or not.
 24. The radionetwork node according to claim 20, wherein the UE is configured todetect that the preamble is associated with the BFR.
 25. The radionetwork node according to claim 24, wherein the UE is configured todetect that the preamble is associated with the BFR by being configuredto detect one of that the preamble is of a set of predeterminedpreambles and the random access resource, used when transmitting thepreamble, is of a set of predetermined random access resources.
 26. Theradio network node according to claim 24, wherein the radio network nodeis configured to, in response to detecting that the preamble isassociated with the BFR, omit adding the temporary identifier to theRAR.
 27. (canceled)
 28. (canceled)